Phonograph



NOV. l, 1938. HEACOCK 2,135,35

PHONOGRAPH Filed Feb. 29, 1936 4 Sheets-Sheet 2 Nov. 1, was. R H HEACOCK 2,135,035

PHONOGRAPH Filed Feb. 29, 1936 4 Sheets-Sheec 3 Nov. l, 1938.

R. H. HEACOCK PI-IONOGRAPH Filed Feb. 29, 1936 4 Sheecs-Sheet. 4

Paterited Nov. 1, was

UNITED STATES 2,135035 PHONOGRAPH Ralph n. Heacock, Oaklyn, N. J. assignor m Radio Oorporation 01 Amerlca, a corporation 01 Delaware Apnlication February 29, 1936, Se1 lal N0. 66,352

17 Olaims. This invention relates to phonogfaphs, and

more particularly to means for insurlng the cation of the record scanning element upon the record at the exact point er polnts from which it is desirecl to have reproduction started.

Under certain circumstances lt is necessary to reproduce from a sound record a deslred sound 'or series of sounds whlch have been recorded intermediate the ends of the record. For example, in radio broadqasting, it frequently is necessary to reproduce the beatlng cf a horses hoofs, the pealing of thunder, the crackling of fire, the pouring of rain, and many similar sounds which can be simulated by numerous relatively simple devices. I-Iowever, for more complex sounds, this becomes very difiicult and the most praetleal way to introduce them in a, broadcast is by reproduction from an already existing phonograph record. .Thus, in broadcasting a scene i nvolving a flre, for instance. a record on which the roaring cf motors, the screaming of sirens and the yells of the exclted crowds have been previously recorded is cut in immediately following one of the actors cries of Fire to produce the natura] background and color characteristic of the scene. Obvlously, lt is essential that the proper portion of the record should be selected from which reproduc- -tion of the desired subject matter ls 1:0 be obtained. Agaln, lt is often deslrable, ln dubbing from an existing record onto a new record, to

takeofi from j;he old record only certain sounds tlon wlth dlsc records.

Heretofore, a nuinber cf attempts have ben made to provlde devices of this sort inconnec- So far as I am aware, however, these devices have only been accurate to within several grooves 0f the deslred' groove,

and the selection of the proper groo.v e, sind part icularly the proper point in that groove from which reproduction is to starb, has been largely a. matter of chance. It is, therefore, a mute specific .object of my lnvention to provlde 1mproved means, in a phonograph of this type, whereby the exacl; point in a desixed groove cor'-' responding to a predeterminecl word or sound may be accurately selected.

Another object of mylnvention is 1;0 provicle improved indexlng mechanism in a phonograph.

of the type sei: forlsh whereby each sound recdrgled on a, record maybe -properl y inclexed, anti the customary hunting therefor consequently eliminated.

Still another object of my invention is to provide improved indexing mechanlsm in a phonograph of the type set Iorth whereby.the record may be indexed to fractlons of a turn and any desired' portion cf a slngle turn er convolutlon of the sound groove thus accurately located.

A further object of my invention is to provlde improved record ce nterlng means whereby the spirally grooved record may be accurately centered with respect 1:0 both the indexing ancl the s'canning mechanisms;

Still a further object of my inventlon is to provide, in a. phonograph, improved means for controlling the location of the record scanning device with respect td the record.

It is also an object of my lnventlon to provide, in a phonograph, improvecl meansfor controlling the engagement of the scanning device with the record.

Another object of my lnventlon ls to provide lmproved indexing means and scanning device controlling means as aforesaid whlch is simple in constructlon and inexpenslve of manufacture, which can reaclily be applled to existlng couventional phonographs, and which, above all, is highly eificient in use.

In accordance wlth my invention I provide the phonograph with a micrometer toward the head of which the pick-up arm is slightly blased by gravity, a pawl or pawl' carrying mmber associated wlth the plck-up arm being arrangetlto contactthe micrometer head and thus determine the posloion cf the plck-up arm. Associated with the pawl ls a, gear havlnga plurality of -yarlous ly colored indlcating teeth or segments by means of which a main, partial setti ng may benbtained,

while a secondary er vernier settlng is obtained' electr omagnet the circult of which is controlled by two switches in parallel, one a manually operable switch and the other a turntable controlled swltch. It ls only when both swltches are open thal: the electromagneli releases the pickup arm to permlt lt to descend onto the record by gravi ty and under the control of a dash-pot devlce. 'Io insure proper centering of the record with resbect t o the plck-up anti the indexlng mechanism by taking up any play between the record center hole and the turntab le splndle, the record is coupled to the turntable by means of a taperedl centerlng pln. lt will be noted that .since gravity is depengied upon for both biasing the pick-izp arm toward the micrometer head and for caus- Ing the pick-up to descend onto the record entirely without the use of catches or latches, there is no possibility of the mechanism sticking or jamming, and i t is always free to work efficiently.

The novel featuresthat I consider character- .Istic of my invention a.re Set forth With particularity in the appended claims. The invention itself, however, both as to its orgam'zation and method of operatin, together with additional objects and advantages there0f, will best be understood from the following description of a specific embodiment thereof, when taken in connection with the accompanying d mwings in which- Figure 1 is a perspective view of a phonograph having my present invention incorporated therem,

Flgure 2 is an enlarged, fragmentary, plan view showing the details of the relation between the pick-up arm, the main indicating gear, the pawl and its mounting platze, the micrometer and the micrometer gauge,

Figure 3 is a sect1fonal view taken on the line III-III of Figure 2,

Figure 4 is an enlarged plan view of the main indicating gear showing the colored teeth or segments thereof,

Figure 5 is a. sectional view taken on the line VV of Figure 2,

Figure 6 is a detail plan view of one of the switches in the electro-magnet circuit and shows the relation thereto of the turntable carried cor 1- trolling cam therefor,

Figu1ye 7 is an enlarged sectional view tanken on the line VII-VII of Figure 1,

Figure 8 is a wiring diagram showing the details of the electromagnet circult, and

Flgure 9 illustrates a representative index chart used in connection with my invention.

Referring more specifically to the drawings', wherein similar reference characters designa.te corresponding parts throughout, 'there is shown a, motor board I which supports a motor 3 (Fig. 8) for driving a turntable spindle 5 (Fig. 7) upon which is mounted a turntable 1. The upper end of the spindle 5 is bored, as shown at 9, and terminates below the surface 1aof the trntable upon which is supported a spirally grooved disc record II having a. center hole I3 axially aligned with the bore 9. A pin I5 which has a cylindrical portion I1 adapted to friotionally fit into the bore 9 and a tapered portion I9 adapted to frict;lonally engage the edge of the record defining the open- 1'ng I3 locks the record to the turntable I and the spindle 5 and fixes 1'I; with respect to the mechanism hereinafter described. It will be noted that the turntable is provided on its periphery with a plurality of substantially evtanly spaced, circumferentially distributed indicia. 2I (Fig. 1), such as numerals, while the record is provided with a marking 23, such 8IS acolored spot.- By loosening the locking pin I5, the record II may be adjusted circumferentially on the turntable and its mark 23 set opposite any one of the indicia 2I or between any two of theni for a. purp0se also presently tobe sei; forth, after which the pin I5 may be depressed to lock the record in place.

Supported on the upper surface of the motor board I and spaced therefrom by a plurality of washers 25 is a supporting bracket 21 through the base 28 of which extend a pa.ir 015 screws 29 which are screwed into the motor board I. The screws 29 are spacecl apart approximately 120- and' a coil sprlng30 is lnserted amund each screw between its head and the base 28. This construction permits tilting oi the bracket member 21 and the structure supported thereby. For tilting the bracket 21, there is provided a, third screw 3I (Fig. 5) which is threaded into a metal inset 33 in the motor board I- located approximately 120 from ea.ch of the screws 29. A metal washer 35 similar to the washers 25 is mounted oh the screw 3I and is in constant engagement with the base 28, and as the screw 3I is manipulated, the bracket 21 is tilted more or less toward the edge Ia of the motor board I, depending upon the direction of rotation of the screw 3I.

The bracket 21 carries a shaft 31 which may be lockecl in place by a. pair of screws 39, a, sleeve 4I having a forwardly extending yoke 43 and a shoulder 45 being r0tatable on the shaft 31. Pivotally mounted intermediate its ends on a horizontal shaft 41 carried by the yoke 43 is a, supporting arm 49 for a record scanning element 5I, such as an electromagnetic or similar pickup device, dapted to cooperate wlth the record II, a slidable weight 53 on the supporting arm 49 serving as a, means of adjusting the needle pressure an the record. T0 the real end of the supporting arm 49 is fixed a steel or other magnetic inember 55, and immediately below the member 55 is a housing-enclosed electromagnet 51 mountod on a bracket 59 which is fixed to the sleeve 4I for rotation therewith. The core 61 of the electromagnet 51 projects through the top of the housing and acts as a mechanical stop to the upward motion of the scanning element 5I. When the scanning element israised, the member 55 is definitely engagedloy the core GI and the scanning element is bald in raised position so long 'as the coil of the electr0xnagnet is energized. As soon, howevex, as the coil is de-energized, the scanm'ng element 5I descends by gravity onto the record and the member 55 is raised away from the core 6I.

In order to cushion the descent of the scar1mng 'element 5I onto the record, a. dash-pot; 63 is fixedly mounted on the shoulder 45 by means of a bracket 65, the piston 61 of the dash-pot being connected to the member 55 by a. connecting rod.

69. Preferably, the piston 61 is provided. with a.

few 011 grooves II on lts periphery in order to insure an accurate a1r seal, and the cylinder of the dash-pot 63 may be provided with a metal insert 13 which has a tapered hole therein into which the tapered and of a. screw 11 Inay be inserted for more or less closing the hole 15 and thus controlling the rate a1: which air Is exhausted from the cylinder through a. port 19.

In this manner, the rate of doscent of the scanning element 5I toward the record upon deenergization of the electromagnet 51 may be coutrolle d.

The circuit for controlling the electromagnet 51 is shown in detail in Flg. 8. Current is supplied from a suitable alternating current source through the leads 8I, 93, a master switch 85, a. step down transformer 81 and a. variable reslstor 89 t: a, copper oxide rectlfier 9I, such as a Rectox unit, the output 013 which is used to energize the electromagnet 51. The motor 3 and a pilot light 93 are also energized from the maln leads 8 I 83, the latter through a step-down transformer 95. Between the rectifier 9I and the electromagnet 51 are a palr 01 switches 91 and 99 which are arranged in parallel and control the current supplied to the electromagnet 51, a coudenser 98 serVing' to ellmlnate sparking of the switches 91 and 99.

- erable either locally or at a remote point.

Since, with the master switch 85 closed, eurrent will be supplied to the electromagnet 51 if either of the switches 91 or 99 1s also closed, lt is evident that both switches 91 and 99 must be open to de-energize the electromagnet. One of these switches, for example 91, may be manually op- The other switch 99 is locat-ed in close proximity to the turntable -'I and is operated by a cam IOI fixed t the under side of the turntable and arranged to engage a rubber roller III3 carried by a pivoted lever IIJ5 the arm III6 of whlch is adapted to engage the spring blade I 99 of the switch 99. Normally, the two contacts cf the switch 99 are in Engagement with each other. During each revolution of the turntable, however, the-cam I9I engages the roller I 93 and forces the arm I96 against the spring blade Ill0 to separate the switch contacts, but the electromagnet 57 still remains energized until the switch 91 is also opened. Thus, when it is desired to de-energize the electromagnet 5'I, the switch 91 is manually opened and held open until the cam IIJI has opened the switch 99 also whereupon the 91 is manually opened, it will be evident that the release of the scanning element is indexed with relation to the turntable, and, through the indicia 2I and the marking 23, with relation to the record II. Thus, the record II may be so adjustecl circumferentially on the turntable l that the scanning element will be released. to engage any predetermined point in any turn or convolution of its spiral groove.

Fixed to the upper end of the sleeve 4I for rotation thereWith is a gear I0'I having a, number of its teeth Ill9 distinctively marked, as by diiferent colors, for example, red, yellow,green, silver, and blue. A disc III is also fixed to the sleeve 4I and is provided with .a. reduced hub portion around which is fitted a plate-like member II3, so that the latter is confined between the gear I0'I and the disc I II but is free to rotate relatively thereto about the axis of rotatiop of the sleeve 4I. The plate II 3 is provided with a cut-away portion I I4, such as a notch, slot, opening 0r the like superimposed over the teeth IIJ9 and of such size as to expose to view only one of the colored teeth I99 at atime. A pawl II5 pivoted on the plate II3 has a dog thereon which is constantly urged into engagement with certain unmarked teeth of=the gear I9'l by maans of' a coll spring III. The plate II3 is also provl'ded with a. shoulder II9 arranged to engage the head of a micrometer I2I carried iri a sleeve I23 on the bracket member 21. Since the gear IIJ'I is fixed to rotate with the supporting arm 49, it is evident that if the shoulder II9 is brought into engage ment with the micrometer head, the particular tooth I99 exposed will constitute a main, rdugh sector er indexfor indexing the radialposltion of the supporting arm 49 and its canningelemnt 5I with relation to the record I I. 'Adjustmentof the micrometer I2I will then provide a vetnler setting or reading to inore accurately indicate' the exact position of the scannin'g 'element5l with respect to the record.

When it is desired to set the mechanism to begin reproduction at a. -desir.ed polnt the sup- During this time, light pressure is applied downwardly on the seanning element 5I so that the needle will not become dislodged from the groove and light pressure toward the gear III! is simultaneously applied to the free end cf the pawl II5 to insure proper e'ngagement of the pawl dog and the gear I0'I. The micrometer setting may qhen be conveniently reacl on the dial scale I25 by means cf an indicator I2'l which is actuated from the micrometer through a hell crank I29, and the reading of the indicator I2'I as well as the color of the particular tooth Ill9 which is exposed view is recorded.

Inasmuch as one or two revolutions of the record II may follow opening of the switch I35 and shutting oft of the motor power, the micrometer head should be backed up a distance corresponding approximately to two grooves, or about .016".

The reading thus obtained may still not be very exact, and the record shouldthe'refore, be played from the adjusted position to ascertaln whether the correct setting has been obtalned. If not, the micrometer I2I is adjusted one way or the other until the proper groove has been located. Veryfrequently, however, the particular Word desired may start from some point in the selected groove other than that a.t which the scanning element engages the groove. For this reason, the record II is made cixcumfuarentially adjustable on the turntable I and the position of the marking 23 with reference to the indicia 2I is also noted and recorded when the exact position in that groove has been located. A series ofreadings similar to the above may be made f0i a plurality of points in a single record and eachof them recorded to provide a table like that shown in Figure 9. For example, it may be f0und that a passage beginning with the words The air is can be roughly located by exposing the green I tooth Ill9 of the gear I ll l and more exactly located when the dial scale I25 reads Adjustment of the record II to provide the exact Iocation of this expression may show that the 'other topics listed in the chart or table shown in Fi'g. 9. By biasing the arm 49 to swing toward the nieter board edge Ia (in other words, toward the micrometer head)- in the n'1anner heretofore dscribed ende a desired setting of the microrheter I2I, the plate ll3.zmd the record II have been made, it is obVious that the arm 49will swing over= the cause engagement of the shoulder II9 with the micrometer head to properly position the needle of the scanning element 5I with respect to the desired point on the record I I.

The spring II! is pfeferably madesufiiciently weak to allow the pawl H5 1:0 sweep over the teeth of the gear I0! without the conventional clicking when light pressure is applied away from the gear 101 on the 1'ree end of the pawl and. to allow easy operation of the plate H3 and the pawl H5 in order to make the operation 015 the device satisfactory when used in combination with records whose recordedgrooves are eccentric to the turntable spindle.- If the scanning elemenl: 5I should come down on' the extreme inward position of one of these eccentrically recorded grooves, then, as the needle is moved back away from the turntable spindle, the backward motion will be absorbed by the mechanism in a slight elongation of the spring l I1, and the needle will, therefore, not be forced from the groove. T0 facilitate a reading of the particular tooth I 09 which is exposed and a reading of the dial scale I25, the pilot lamp 93 is preferably mounted on top of the bracket member 21. If desired, a second pilot lamp may be mounted in the vicinity of the turntable rim to facilitate reading cf the indicia 2I.

From the foregoing description, 1t will be apparent that I have provided indexing mechanisrn by means of which the exact point; on a record at which a predetermined word or sound has been recorded may be accurately located. As pointed out previously, gravity alone controls the 'movement of the supporting arm 49 both upon Conserecord, the suppo'rting arm 49 is free to move in;

any direction, andno springs or other constant loads are present which tend to,force the needle either in one direction or the other. 'I'he shoulder I I9 engages the micrometer head until the needle is actually pulled away by the record groove, and therefore there is no possibility of inaccurate lateral wavering o1 the supporting arm 49 when the electromagnet 51 has been deenergized. Moreover, the pin I5 accurately centers the record by removing all play between the record and the turntable spindle 5, and since the rotative position of the record with relation to the turntable is fixed, it is posslbleafter removing the record II, to replace it on the turntable and bring the ne'edle down on the exact word er sound which may be desired by pre-setting the index mechanism; and this will be true even where, as pointed out above, the recorded grooves are eccentric to the ceni;er hole o1. the record. It is also to be noted that, inasmuch as the beginning of desceht of the scanning member out accurately locating the parts with relatlon to= each other on each new set-up.

Although I have described my invention in conSiderable detail, I am fully aware that many modificatlons thereof and changes therein may,

be made without departlng from the scope therecf. I, therefore, desire that my invention shall not be limited except insofar as is necessitated by the prior art and by thespirlt of the appended claims.

I claim as my invention:

1. In a phonograph, a supporting arm, a record Scanning element carried thereby, and. means associated with said supporting arm for determining the position of said scanning element with respect to the record, said means including a plurality of position determining devices one of which is adapted 130 approximately locate said scanning element with reference to a predetermined point on the record and another of which is adapted 1:0 more acc-urately locate said scanning element with reference to said point.

2. The invention set forth in claim 1 characterz'zed in that said position determining devices comprise visible indicators.

3. The invention sei: forth in claim 1 characterized in that said position determining devices comprise visible indicators each having a difierent identifying characteristic.

4. In a phonograph, the combination of a pivoted supporting arm, a record scanning element carried thereby, a stop member adjustably a ssoc'atedwith said supporting arm, sai d supporting member being constantly biased toward said stop member when said scanning element is free of the record, and means movable with said supporting arm and arranged to engage said stop member whereby to determine the-position of said scanning element with 'respect to the record.

5. In a phonograph, the combination of a pivoted supporting arm, a record scanning element carried thereby, a micrometer assoc'ziated with said supporting arm, a member rotatably mounted on the pivotal axis of said supporting arm, and means for releasably locking said member to said supporting arm for rotation therewith, 'said member being arranged to engage the head of said micrcmeter whereby 130 determine the pogiti0n of said scanning element with respect to the record.

6. In a phonograph, the combination cf a supporting arm pivotally mounted for movement across a record, a record scanning element carried by said supporting arm, a micrometer associated with said supporting arm, a member fixed said supporting arm for movement therewith and having a plurality of sectors thereon, a second member mounted for rotation relative to said first named member and having a cut-away portion therein through which only one of said sectors may be exposed to view at a time, and means for releasably locking said. second named member said first named member whereby to cause it to move as a unit with said supporting arm, said secondnamed member having a shoulder adapted to engage the head of said micrometer Whereby to determine the position of said s :anning element with respect to the record.

7. In a phonograph, the combination of a supporting. arm pivotally mounted for movement across a record, a record scanning element carried thereby, a micrometer associated with said supporting arm, a gear fixed to said supporting arm for movement therewith about its pivotal axissaid gear having a plurality of variously 001- ored teeth thereon, a member mounted for rotation about said axis relative to said supporting arm and gear, said member having a notch therein through which only one of said colored. gear teeth may be exposed 120 view at a time and having a shoulder thereon adaptedio engage' the head of said micrometer, and a pawl pivotally mounted on said member and adapted to engage said gearto rele'asably lock said member thereto, the adjustment of said member relative to said gear serving to provide an initlal setting for approximately locating said scanning element with 'respect to a predetermined point on said record, and the adjustment of said micrometerserving to provide a vernier setting for more precisely locating said scanning element with respectto said.

record point.

8. The inventi on set' forth in claim 7 characterized in that said supporting arm is'so biased that it will move in a di1ection to cause said shoulder to engage said micrometer head when the scanning member is free of the record.

9. In a phonograph, the combination of a turntable having a plurality of indicia thereon at regularly spaced intervals, and a record supported thereby said record having a reference mark thereon by means of which the record may be adjusted circumferentially an said turntable with respect to said indibia.

1 0. In a phonograph, the combination of a vices one of which is adapted to approximately locate said scanning element with reference to said groove and ano ther of which is adapted t more precisely locate said scanning element wlth reference to said groove, and said record being circumferentially adjustable on said turntable to provide exact location of a predeterminecl point in said groove with respect to said scanning member.

11. In a phonograph, the combinatlon of a. turntable having a plurality of indicla on the periphery thereof at regulariy spaoed lntervals, a spiraliy grooved record. supported thereby, said record having a reference mark thereon by mea.ns 015 which the record may be adjusted cicumierentially o n said tnrntable with respect to said indicia, a supporting arm pivotally mounted for movement across said record, a record scanning element cariied thereby, a mi'orometer associated with said supporting arm, a gear flxed to said supporting arm for movement therewith about its pivotal axis, said gear having a plurality of variously colored teeth thereon, a member mounte d for rotation about said axis relative to said supporting arni'and gear, said member having a notch therein through which onlyone 015 said colored gear teeth may be exposed to view' at a time and having a shoulder thereon adapted to engage the head of said micrometer, a pawl pivotally mounted on said member and having a dog adapted to engage said gear to releasably lock said member thereto, and spring means constantly urging said do g into engagement with said gear,

the adjustment of said member relative to said gear serving to provide an Initial setting for approximately locating said scanning element with respect to a predetermined groove on said record, the adjustment of said micrometer serving to provide a vernier setting for more precisely locating said scanning member with respect to said groove, and the circumferential adjustment of said record serving to exactly locate a predetermined point in said groove with respect to said scanning element.

12. In a phonograph, a record scanning element supporting arm mounted on a horizontal axis for pivotal movement with respect to the record, electromagrfetic means associated with said arm and adaptiad, when energized, to hold said scanning element out of engagementwith the record, and a dashpot device also associated with said arm adapted to control the approach of said arm toward said record when said electromagnetic means is de-energized.

13. In a phonograph the combination of a. record scanning element supporting arm mounted on a horizontal axis fl r pivotal moVemen't with respect to the re'cord, electromagnetic means associated lwith said arm and adapted, when energized, to hold said scanning elementout of turntable, and means operable by said turntable .to control the opening and closing cf said one switch during each revolution of said turntable.

15. In a phonograph, the combination of a turntable, a record scanning element supporting arm mounted on a horizontal axis for pivotal movement toward and away from said turntable, an electromagnet associated with said arm and adapted, when energized, to hold said scanning element away from said turntable, an energizing circuit for said.electromagnet including a pair of circuit controlling switches in parallel, one of said g.witches being located in proximity to said tumtable, and a cam on said turntable in cooperative relation to said one switch for controlling the opening and closing thereof during each revolution cf said turntable.

16. In a phonograph, thecombination of a turntable, an electrically actuable member, mechanism Ior actuating said member, switch vmeans for controlling said mechanism, and a cam on said tumtable for controlling the opening and closing of said switch means.

1'7. In a phonograph, the combination of a. turntable an electrically actuable member mechanism for actuating said member, switch means for controliing said mechariism, and a cam on said tumtable in cooperative relation to said switch means, said cam being so constructed and arranged as to control the openlng and closing of said switch mean's ab least once during each -revolution 01 the turntalale. Y

RALPH H. HEACOCK. 

